Manitowoc MLC150-1, Service Maintenance Manual

Page: 171 / 206

Manitowoc
Published 03-21-2021, Control # 264-01
7-11
MLC150-1 SERVICE/MAINTENANCE MANUAL POWER TRAIN
7
ADJUSTING THE ENGINE THROTTLE
The engine throttle assembly consists of an electronic hand
throttle control in the left console and an electronic foot
throttle control on the cab floor. There is no mechanical
linkage between the throttle controls.
Electronic signals from the throttle controls are transmitted to
the crane control system, and the control system increases
and decreases engine speed accordingly.
Hand Throttle Control
The hand throttle control does not require adjustment and is
not repairable.
Foot Throttle Control
See Figure 7-8 for the following procedure.
If there is a problem with the foot throttle, it is best to either
replace it or send the unit to your Manitowoc Dealer for
repair.
However, if field disassembly was done, use the following
procedure to re-assemble and calibrate the throttle control.
NOTE: The foot throttle control was properly assembled
and calibrated at initial installation and should not
require further attention.
Steps 1 through 8 must be done on a clean work bench.
1. To assemble the right foot pedal shaft (3) and the torsion
spring (5) into the foot pedal housing (1), first assemble
the spring onto the shaft by inserting the lug on one end
of the spring into the hole in the head of the shaft.
2. Insert the shaft into the cavity in the bottom of the
housing, through the roller bearing (8), and into the foot
pedal (2).
The lug on the outboard end of the torsion spring must
engage the hole in the housing (see A-A).
3. Insert the left foot pedal shaft (4) into the cavity in the
bottom of the foot pedal housing, through the roller
bearing, and into the foot pedal.
4. Rotate the foot pedal as needed and install the roll pins
(10) through the holes in the foot pedal and the foot
pedal shafts (see Pedal Position A).
5. Install the setscrew (17) only partway into the threaded
hole. Do not allow the setscrew to contact the right foot
pedal shaft at this time.
6. Rotate the foot pedal approximately 40° to Pedal
Position B (low idle). The flat on the head of the right foot
pedal shaft should be parallel with the surface X on the
foot pedal housing.
7. Turn in the setscrew until it just contacts the flat on the
head of the right foot pedal shaft (see A-A).
8. Install the potentiometer (6) and calibrate the foot
throttle as follows.
a. Solder the control wires to the potentiometer leads
as follows (see B-B):
- Black wire (12) to the outer lead
- Green wire (13) to the middle lead
- White wire (14) to the fixed resistor lead
b. Turn the potentiometer shaft fully counterclockwise
as viewed from the shaft end.
With a supply voltage of 25 V
DC
to 26 V
DC
available
at the white wire, 0 V
DC
should be present at the
potentiometer output (green wire) lead.
c. With the pedal at Pedal Position B, insert the
potentiometer into the cavity in the bottom of the
housing (see B-B). Insert the potentiometer shaft
into the end of the left foot pedal shaft (4) and
tighten the setscrew (18).
d. Rotate the foot pedal to the high idle position and
adjust the setscrew (17) to hold the foot pedal at this
position.
e. Rotate the potentiometer housing to obtain an
output of 0.9 V
DC
to 1.0 V
DC
.
f. Apply silicone sealant RTV-162 between the
housing and potentiometer. Do not get sealant on
the shaft. Allow sealant to cure before proceeding to
the next step.
g. After the sealant has cured, check the
potentiometer output for 0.9 V
DC
to 1.0 V
DC
with the
foot pedal at the high idle position.
h. Remove the setscrew (17) and apply Loctite #243 to
the threads. Install and adjust the setscrew to obtain
a low idle pedal position output of 2.9 V
DC
to
3.0 V
DC
.
9. Install the assembly onto the crane.
REFERENCE
ONLY